Thanks to JAXA—the Japanese Space Agency—the astronauts aboard the International Space Station have some new pets to keep them company. A small school of Medaka fish that will be used to study the impacts of radiation, muscle atrophy, and bone degradation in space.

The AQH Aquatic Habitat (because fish tank sounds too low-tech) features a specially designed filtration system that will keep the fish alive for up to 90 days (sorry guys!), allowing them to re-produce multiple times during their stay, which will be a first in zero gravity. The habitat also automatically feeds the fish, simulates night and day lighting, and has a special chamber for holding air that keeps the water sufficiently oxygenated.

And the reason the research is being conducted on Medaka fish, instead of run-of-the-mill goldfish? As you can see in that shot from the live video feed, the fish are actually see-through, which makes studying and monitoring their inner workings considerably easier. We're just curious if they can still be flushed down those space toilets after they die. [NASA via Neatorama]